Based on the cooperative virulence index (c.f.) and LC50 of fipronil, the interaction effect between short-term heat pretreatment and fipronil on 2nd instar larvae of diamondback moth (DBM), Plutella xylostella (Linnaeus), was assessed. The results suggested that pretreatment of the tested insects at 30 Â°C for 2, 4 and 8h could somewhat decrease the toxicity of fipronil at all set concentrations. The LC50 values of fipronil increased after heat pretreatment and c.f. values in all these treatments were below zero. These results indicated that real mortalities were less than theoretical ones and antagonism was found in the treatments of fipronil at 0.39 and 0.78 mg/L after heat pretreatment at 30 Â°C at 2, 4 and 8 h. However, pretreatment at 30 Â°C for 12h could increase the toxicity of fipronil at all set concentrations, the LC50 of fipronil decreased after heat pretreatment and c.f. values in all these treatments were above zero, which indicated real mortalities were higher than theoretical ones. Pretreatment of the tested insects at 35 Â°C for 2, 4, 8 and 12h was found to increase the toxicity of fipronil at all set concentrations which resulted in the decrease of LC50 values of fipronil and c.f. above zero in all treatments with only one exception. Most interactions were assessed as synergism. The results indicated that cooperative virulence index (c.f.) may be adopted in hormetic effect assessment.

Diamondback moth, Plutella xylostella, is a major worldwide pest of cruciferous vegetables and has developed high levels of resistance against many pesticides. The current research presents the joint action of destruxin A and chlorantraniliprole against resistant strain of Plutella xylostella...

Bacillus thuringiensis insecticidal crystal proteins (ICPs) and vegetative insecticidal proteins (VIPs) have been widely used as a kind of safe bio-insecticides. A problem that has been of concern worldwide is how to improve their insecticidal activities. In this study, to determine the...

The prey preference of Heteropoda garciai, Olios mahabangkawitus, Ctenus floweri, and Pardosa apostoli was examined on Spodoptera litura and Plutella xylostella in laboratory. These spiders showed a clear preference for P. xylostella compare to S. litura. However, there was no significant...

Unraveling the relationship between adult oviposition preference and offspring performance is central to understanding the evolution of plant-insect interactions. In the present study, we collated previously reported data, including our own, of adult oviposition preference and offspring...

Plants respond to insect feeding damage by releasing a variety of volatiles from the damaged site. The profile of the volatiles emitted from undamaged and mechanically damaged plants is markedly different. The diamondback moth (DBM), Plutella xylostella L, which feed on the plants of the family...

Infection of the pebrine disease has been found to be highly virulent and harm the cocoon yield as well as characters of silkworm Anthereae mylitta. Therefore, an attempt was made to evaluate the impact of parasite Nosema species on the ecorace (Sukinda) of A.mylitta in respect of transovarial...

The author reflects on how to detect fungal virulence in an alternative mini-host by using bioluminescence. Topics discussed include a study of infected animals by bioluminescence, infection monitored from wax moth larvae by using non-toxic and water-soluble formulation of the substrate...